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Collaborating Authors

 Sarangan, Venkatesh


Predicting Vehicular Travel Times by Modeling Heterogeneous Influences Between Arterial Roads

AAAI Conferences

Predicting travel times of vehicles in urban settings is a useful and tangible quantity of interest in the context of intelligent transportation systems. We address the problem of travel time prediction in arterial roads using data sampled from probe vehicles. There is only a limited literature on methods using data input from probe vehicles. The spatio-temporal dependencies captured by existing data driven approaches are either too detailed or very simplistic. We strike a balance of the existing data driven approaches to account for varying degrees of influence a given road may experience from its neighbors, while controlling the number of parameters to be learnt. Specifically, we use a NoisyOR conditional probability distribution (CPD) in conjunction with a dynamic Bayesian network (DBN) to model state transitions of various roads. We propose an efficient algorithm to learn model parameters. We also propose an algorithm for predicting travel times on trips of arbitrary durations. Using synthetic and real world data traces we demonstrate the superior performance of the proposed method under different traffic conditions.


Cracks Under Pressure? Burst Prediction in Water Networks Using Dynamic Metrics

AAAI Conferences

Ranking pipes according to their burst likelihood can help a water utility triage its proactive maintenance budget effectively. In the research literature, data-driven approaches have been used recently to predict pipe bursts. Such approaches make use of static features of the individual pipes such as diameter,length, and material to estimate burst likelihood for the next year by learning over past historical data. The burst likelihood of a pipe also depends on dynamic features such as its pressure and flow. Existing works ignore dynamic features because the features need to be measured or are difficult to obtain accurately using a well-calibrated hydraulic model. We complement prior data-driven approaches by proposing a methodology to approximately estimate the dynamic features of individual pipes from readily available network structure and other data. We study the error introduced by our approximation on an academic benchmark water network with ground truth. Using a real-world pipe burst dataset obtained from a European water utility for multiple years, we show that our approximate dynamic features improve the ability of machine learning classifiers to predict pipe bursts. The performance (as measured by the percentage of future bursts predicted) of the best forming classifier improves by nearly 50% through these dynamic features.